Express-News staff writer Terrence Thomas provides a glimpse at some of the top storylines this season:

Is this the year O’Connor’s decade-long reign over District 27-6A might end?

The Panthers have won 10 straight district titles, shared or outright, and are 140-3 in league play since September 2006. They have compiled district winning streaks of 68 and 60 matches — the latter of which they are currently riding. So, it’s a safe bet not to discount O’Connor’s chances of continuing its dominance.

But if there is a year that someone supplants the Panthers, this definitely could be it.

Coach Kristen Daniell guided Clark to the Region IV-6A final a year ago, losing a five-set thriller to Churchill. The Cougars return six starters. Brandeis returns four starters, Brennan brings back five, and Warren, which will be led by coach Jaci Barrientes, who previously was at Highlands, returns five starters from a team that was in the playoff hunt until the final weeks.

All four District 29-4A playoff teams made it to at least the regional quarterfinals in 2014, with Fredericksburg and Boerne advancing to the regional tournament. Which area district has the potential to accomplish the feat this season?

On paper, it appears as if District 26-4A is setting up as the successor to that throne. Three teams — Wimberley, Navarro and Canyon Lake — registered 30-win seasons a year ago, and each could be as strong if not stronger this year.

La Vernia missed the playoffs last year for the first time since the mid-1980s, but was in the race for a playoff berth until the end. The Bears return four starters.

The early prognostication is that any of the aforementioned teams could capture the district championship.

Alamo Heights is coming off its best season, recording a school-record 42 wins and advancing to its first regional final. What will the Mules do for an encore?

Alamo Heights has some big voids to fill, namely those of All-Area Super Team performers McKay Kyle and Devon Sadosky, who both graduated. Coach Courtney Patton, though, has built a program where deep playoff runs are now the norm, and the return of setter Hannah Lackey and middle hitter Callie Cook gives Patton a foundation to build around.

The Mules’ stiffest challenge likely will come from Kerrville Tivy and Boerne Champion in District 27-5A, and Dripping Springs. Dripping Springs edged Alamo Heights in five sets in the Region IV-5A final in 2014 — and the Tigers, with at least three Division I prospects, enter this season nationally ranked.